GB1250695A - - Google Patents

Abstract

1,250,695. Precipitation. SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ N.V. 15 Dec., 1969 [16 Dec., 1968], No. 60938/69. Heading G1X. [Also in Divisions C4 and C5] In the separation of hydrocarbon mixtures by treatment with an aqueous solution of an adduct forming agent, e.g. urea, thiourea or antimony trichloride, followed by separation of the adduct from the remainder of the mixture, the pressure and temperature in the adduct forming-zone are such that the solution of adduct-forming agent boils and is concentrated by evaporation during the treatment. The evaporation can be continued until a suspension of adduct containing grains have been formed or until the solution has lost practically all of its water, in which case fire particles containing the adduct are formed. The solution of adduct forming agent and the hydrocarbon mixture can be introduced into the zone by squirting or atomising either separately or in admixture. An aqueous solution of urea 3 is mixed with a hydrocarbon feed 1 and atomised into the zone 2 which is maintained at 30-70‹C. A diluent 4, e.g. light gas oil or kerosine boiling from 150-250‹C, can be added as such or admixed with the solution of adduct-forming agent and/or the feed 1. The solid adduct is separated at 15 from the stream 14, a liquid 25 and the adduct 17. The adduct is decomposed at 19, using hot water and/or steam from line 20, to form a mixture which is separated at 23 into an oil stream 24 and an aqueous solution of urea which is recycled to the zone 2. The water vapour from zone 5 is either condensed at 6 and the condensate passed to line 20 to decompose the adduct at 19 or compressed at 26 and passed into zone 19. The stream 25 can be separated to recover the diluent for recycle to zone 2 and the raffinate which can in part be recycled to the zone 2.